1. Field
The following description relates to a cathode active material, a cathode and a lithium battery each including the cathode active material, and a method of preparing the cathode active material.
2. Description of the Related Art
Transition metal compounds, such as LiNiO2, LiCoO2, LiMn2O4, LiFePO4, LiNixCo1-xO2 (0≦x≦1), and LiNi1-x-yCoxMnyO2 (0≦x≦0.5, 0≦y≦0.5), and lithium oxides of these transition metal compounds are widely used as cathode active materials for lithium batteries.
Such a cathode active material is mixed with a binder, a conducting agent, or the like to obtain a cathode active material slurry, which is then coated on a substrate to form a cathode active material layer, thereby manufacturing a cathode.
A surface state of the cathode active material layer depends on the state of the cathode active material which makes up about 70 to 90 wt % of the cathode active material slurry.
When the surface state of the cathode active material layer is poor due to the presence of protrusions or cracks thereon, an additional process for removing them is required for manufacturing a battery or even worse—a cathode having such a poor cathode active material layer may not even be suitable to be used for manufacturing a battery. Furthermore, a battery including a cathode with such a cathode active material layer having poor surface characteristics may cause reduced performance.
Therefore, there is a need for a method of removing protrusions from a cathode active material layer surface.